A pants-type disposable diaper which has a waist opening at an upper end and a pair of leg openings on a lower part is conventionally used as one type of absorbent product for receiving excrement from a wearer (see Japanese Patent Application Laid-Open No. 2009-72532 (Document 1) and Japanese Parent Publication No. 4190132 (Document 2)).
In a disposable diaper disclosed in Document 1, an absorbent main body is bonded on an inner surface of an outer covering member having an inner layer sheet and an outer layer sheet, and an end portion of the absorbent main body in a longitudinal direction is covered with the inner layer sheet which is folded inward. Also in a disposable diaper disclosed in Document 2, an end portion of an absorbent main body in a longitudinal direction which is bonded on an inner surface of an outer covering member is covered with a covering sheet which is different from the outer covering member. The outer covering member has double-layered structure of an inner layer nonwoven fabric and an outer layer nonwoven fabric, and an end portion of the covering sheet in the longitudinal direction is covered with the outer layer nonwoven fabric which is folded inward.
Recently, in pants-type disposable diaper, comfort level of wearing a disposable diaper is progressively improved by thinning and softening of its outer covering sheet. On the other hand, in a pants-type disposable diaper, in order to prevent a portion in the vicinity of a waist opening, to cover a waist of a wearer (hereinafter, the portion is referred to as a “waist covering portion”), from being damaged by tension when putting the disposable diaper on the wearer, body pressure when the disposable diaper is worn, or the like, it is required to increase strength of the waist covering portion to a certain level.
In the disposable diaper disclosed in Document 1, a waist covering portion is formed by making the inner layer sheet of the outer covering member into double-layered structure. Since the inner layer sheet needs to be thickened for increasing strength of the waist covering portion, it is difficult to improve softness of the outer covering member while maintaining strength of the waist covering portion. In addition, in the disposable diaper disclosed in Document 2, a waist covering portion is formed by making the outer layer nonwoven fabric of the outer covering member into double-layered structure and locating the covering sheet therebetween. Thus, since mainly the outer layer nonwoven fabric needs to be thickened for increasing strength of the waist covering portion, it is not easy to improve softness of the outer covering member while maintaining strength of the waist covering portion.